Solar Cell Device Physics, 2nd Edition

APPENDIX B

Radiative Recombination

In this text, “radiative recombination” refers to the net band-to-band recombination traffic resulting from the path₁ and path₂ traffic seen in Figure B.1. This type of recombination involves photons and perhaps phonons for energy emission (path₁) and assimilation (path₂) but there is no involvement of energy-gap states. Path₁ (electrons or holes recombining per time per volume) requires the presence of an electron concentration n in the conduction band and the presence of a hole concentration p in the valence band and is proportional to their product; i.e.,

(B.1)

Figure B.1 Band-to-band traffic.

This np product–dependence ...